High resolution laserable assemblages for laser-induced thermal image transfer

ABSTRACT

This invention relates to laserable assemblages for use in laser-induced thermal transfer imaging which result in improvements in resolution and toughness in the transferred image when two binders differing in glass transition temperature are incorporated into the transfer layer.

This application claims the benefit of Provisional application Ser. No.60/290,296, filed May 11, 2001.

FIELD OF THE INVENTION

This invention relates to improved laserable assemblages for use inlaser-induced thermal transfer imaging. In particular, it relates toimprovements in resolution and toughness in the transferred image whentwo binders differing in glass transition temperature are incorporatedinto the transfer layer. The invention is of particular utility in theformation of color filters in high resolution liquid crystal displays.

BACKGROUND OF THE INVENTION

Liquid crystal display (LCD) devices have become increasingly importantin displays which require very low consumption of electrical power orwhere the environment dictates a lightweight, planar, flat surface; Forexample, LCDs are used in display devices such as wristwatches, pocketand personal computers, and aircraft cockpit displays. When there is aneed to incorporate a color display capability into such displaydevices, a component called a color filter is used. For the device tohave color capability, each pixel is aligned with a color area,typically red, green, or blue, of a color filter array. Depending uponthe image to be displayed, one or more of the pixel electrodes isenergized during display operation to allow full light, no light, orpartial light to be transmitted through the color filter area associatedwith that pixel. The image perceived by a user is a blend of colorsformed by the transmission of light through adjacent color filter areas.

A major contributor to the cost of color LCDs is the color filter. Fourcolor filter manufacturing methods are known in the art, viz., dyegelatin, pigmented photoresist, electrodeposition and printing. Thepigmented photoresist method offers the best trade-off of degradationresistance, optical properties, and flexibility along with highresolution, and is generally preferred. While conventionalphotolithographic materials and methods may be employed in thephotoresist method, it suffers from the high cost and inconvenienceassociated with numerous process steps, some involving wet chemistry.

Laser-induced thermal transfer processes are well-known in applicationssuch as color proofing and lithography and have been described in, forexample, Baldock, U.K. Patent 2,083,726; DeBoer, U.S. Pat. No.4,942,141; Kellogg, U.S. Pat. No. 5,019,549; Evans, U.S. Pat. No.4,948,776; Foley et al., U.S. Pat. No. 5,156,938; Ellis et al., U.S.Pat. No. 5,171,650; and Koshizuka et al., U.S. Pat. No. 4,643,917.

As is known in the art, laser-induced processes use a laserableassemblage comprising (a) a donor element containing the material to betransferred in contact with (b) a receiver element. The laserableassemblage is exposed to a laser, usually a pulsed infrared laser,resulting in transfer of material from the donor element to the receiverelement. To form an image, exposure takes place over a small region ofthe laserable assemblage at any one time, so that transfer of materialfrom the donor element to the receiver element can be built up one pixelat a time. Computer control of the laser produces transfer with highresolution and at high speed. The laserable assemblage, upon imagewiseexposure to a laser as described supra, is henceforth termed an imagedlaserable assemblage.

For the preparation of images for proofing applications and in photomaskfabrication, the imageable component comprises a colorant. For thepreparation of lithographic printing plates, the imageable componentcomprises an olephilic material which will receive and transfer ink inprinting.

Laser-induced processes are fast and result in transfer of material withhigh resolution. However, in many cases, the resulting transferredmaterial does not have the required durability. In dye sublimationprocesses, light-fastness is frequently lacking. In ablative and melttransfer processes, poor adhesion and/or durability can be a problem. InU.S. Pat. No. 5,563,019 and U.S. Pat. No. 5,523,192, improved multilayerlaserable assemblages and associated processes are disclosed that doafford improved adhesion and/or durability of the transferred images. InU.S. Pat. No. 6,051,318 an improved donor film for use in the productionof color filters is disclosed. U.S. Pat. No. 6,143,451 discloses alaser-induced thermal image transfer imaging process characterized bythe use of an ejection layer which affords advantages in the finalimaged product.

As is known in the art, the transfer layer in a laserable assemblagealways contains some sort of binder, generally a polymeric binder. Thebinder serves to hold together the colorant and any adjuvants theretobefore, during and after the image transfer process is effected, forminga single cohesive, homogeneous mass. It is found that the physicalproperties of the binder have significant effect on the properties ofthe transferred image. In particular, it has been found in the practiceof the art that binders characterized by glass transition temperaturesnear or below room temperature provide good toughness and durabilitywith superior adhesive properties, but often at the expense ofresolution. On the other hand, binders characterized by glass transitiontemperatures well above room temperature provide superior resolution butat the expense of toughness, durability, and adhesion. Practicalapplication of laser-induced thermal image transfer to high resolutionapplications such as color filter formation requires toughness andadhesion sufficient to permit survival of the transferred image duringthe remainder of the manufacturing process. The resolution requirementsfor the color filter application are extremely demanding, and littletrade-off can be made while preserving utility in the application.

Aqueous blends of colloidally dispersed polymers for use in makingorganic coatings which are hard and ductile at ambient temperature andwhich remain stiff and elastic at elevated temperature are disclosed inMazur et al, U.S. Pat. No. 6,020,416. The surprising combination ofproperties is attributed to the use of high molecular weight polymersdiffering in glass transition temperature.

SUMMARY OF THE INVENTION

The present invention provides for a novel donor element suitable forincorporation into a laserable assemblage, wherein the donor elementcomprises a substrate, a metallic or carbon, heating layer, one or moretransfer layers and an optional ejection layer, said novel donor elementfurther comprising

a transfer layer deposited on said heating layer, said transfer layercomprising an imageable component and a binder composition comprising afirst polymeric binder and a second polymeric binder, said firstpolymeric binder being characterized by a glass transition temperatureat least 20 centigrade degrees higher than the glass transitiontemperature characteristic of said second polymeric binder. In someembodiments a donor support may also be present. In a preferredembodiment, the substrate is polymeric.

The present invention further provides for a laserable assemblagecomprising:

a donor element, wherein the donor element comprises a substrate, ametallic or carbon heating layer, one or more transfer layers and anoptional ejection layer, further comprising

a transfer layer deposited on said heating layer, said transfer layercomprising an imageable component a binder composition comprising afirst polymeric binder and a second polymeric binder, said firstpolymeric binder being characterized by a glass transition temperatureat least 20 centigrade degrees higher than the glass transitiontemperature characteristic of said second polymeric binder;

and a receiver element in effective contact with the transfer layer ofthe donor element. In some embodiments a donor support may also bepresent.

Further provided in the present invention is an imaged laserableassemblage comprising an imageable component and a binder compositioncomprising a first polymeric binder and a second polymeric binder, saidfirst polymeric binder being characterized by a glass transitiontemperature at least 20 centigrade degrees higher than the glasstransition temperature characteristic of said second polymeric binder.

Also provided in the present invention is an image disposed upon asubstrate, the image comprising an imageable component and a bindercomposition comprising a first polymeric binder and a second polymericbinder, said first polymeric binder being characterized by a glasstransition temperature at least 20 centigrade degrees higher than theglass transition temperature characteristic of said second polymericbinder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the optical density versus drum speed of theimages transferred in Examples 1-4.

FIG. 2 is a graph showing the optical density versus drum speed of theimages transferred in Examples 5-8.

FIGS. 3A-G illustrate all the steps in the thermal imaging process.

FIG. 4 is a photomicrograph for the image transferred according toExample 9.

FIG. 5 is a photomicrograph for the image transferred according toExample 12.

FIG. 6 is a photomicrograph for the image transferred according toExample 16

FIG. 7 is a photomicrograph for the image transferred according toExample 21.

DETAILED DESCRIPTION OF THE INVENTION

The laserable assemblage of the present invention combines the benefitsin toughness, durability and adhesion of a binder characterized by arelatively low glass transition temperature, and the high resolution ofa binder characterized by a relatively high glass transition temperatureby combining two or more polymeric binders at least one pair of whichsaid binders differ in glass transition temperatures by at least 20centigrade degrees.

According to the present invention a laserable assemblage is formedaccording to means known in the art. Suitable uses for laser thermalimage transfer processes employing laserable assemblages include anyapplication in which solid material is to be applied to a receptor in apattern. The laserable assemblage of the present invention is suitablefor use in any such application where laserable assemblages are useful.Preferred uses include color proofing, the formation of color filterarrays, photomasks, and photolithography. Other uses include but are notlimited to imagewise deposition of magnetic materials, fluorescentmaterials, and electrically conducting materials on suitable receivers.

In a particularly preferred embodiment, the laserable assemblage of thepresent invention comprises crosslinkable binders which are particularlywell-suited for use in the formation of color filter elements for use inliquid crystal display (LCD) devices.

The formation of laserable assemblages, the components employed for theformation thereof, and the methods of their use are well-known in theart, and are described in considerable detail therein. In U.S. Pat. No.5,563,019, incorporated herein, by reference in its entirety, and U.S.Pat. No. 5,523,192, incorporated herein by reference in its entirety,are described improved multilayer laserable assemblages and associatedprocesses. In U.S. Pat. No. 6,051,318, incorporated herein by referencein its entirety, an improved donor film for use in the production ofcolor filters is disclosed. U.S. Pat. No. 6,143,451, incorporated hereinby reference in its entirety, discloses a laser-induced thermal imagetransfer imaging process characterized by the use of an ejection layerwhich affords advantages in the final imaged product

The laserable assemblage of the invention comprises (a) a donor elementthat contains the imageable,component and two or more polymeric bindersat least one pair of which said binders differ in glass transitiontemperature by at least 20 centigrade degrees, and (b) a receiverelement in effective contact with said donor element. In use, thelaserable assemblage is imagewise exposed to a laser, usually a pulsedinfrared laser, resulting in transfer of material imagewise, commonlyone pixel at a time, from the donor element to the receiver element.

Upon exposure and imagewise transfer of material, the resultinglaserable assemblage is termed an imaged laserable assemblage whichcomprises both the receiver element with the transferred image and thedonor element with the non-imaged areas still on it. Preferably, theimaged laserable assemblage is separated into the imaged donor elementand the imaged receiver element. To use a photographic analogy, afterimaging the receiver element bears the positive image and the donorelement bears the negative image. Either the imaged donor element and/orthe imaged receiver element can represent imaged products in accordancewith this invention. The imaged products of the invention comprise animageable component and two or more binders at least one pair of whichsaid binders differ in glass transition temperatures by at least 20centigrade degrees.

Donor Element

As is well-known in the art and in accordance with the presentinvention, the donor element shown in FIG. 3A comprises a polymericsubstrate (1), a heating layer (2), a transfer layer (3) and an optionalejection layer (not shown). Each of these layers has separate anddistinct functions as described, infra. In certain embodiments, a donorsupport can also be present. It will be understood by one of skill inthe art that the specific functions of each of said layers may undervarious circumstances be consolidated into one or more layers in a widevariety of ways particular to the particular embodiment of theinvention. However, preferably, and in the general case, a discretelayer embodies each function to be performed. It is that preferredembodiment which is described hereinbelow.

Substrate

Materials suitable for use as the donor substrate (1) include but arenot limited to poly(ethylene terephthalate) (PET), polypropylene,polyethylene, polyvinyl chloride, and flexible glass. Preferred polymersfor the substrate are polyvinyl chloride and PET. Most preferred is PET.

If the laserable assemblage is to be imaged through the donor substrate,the substrate should be capable of transmitting most of the laserradiation with minimal deleterious effect on the substrate.

Numerous additives, such as are known in the art, may be present in thesubstrate as long as they do not interfere with the essential functionof the substrate. Examples of such additives include but are not limitedto coating aids, flow additives, slip agents, antihalation agents,antistatic agents, and surfactants.

In the preferred embodiment, one or more plasticizers such as aredescribed in the art, is incorporated into the polymeric substrate byordinary means to achieve the desired flexibility.

The polymeric substrate typically has a thickness of about 25micrometers to about 250 micrometers, preferably about 50 micrometers toabout 150 micrometers. The most preferred thickness is about 75micrometers to about 100 micrometers.

Heating Layer

The heating layer (2) is deposited on the polymeric substrate by anysuitable method known in the art including sputtering, vacuumdeposition, chemical vapor deposition, and electron beam deposition. Theheating layer may consist essentially of a metal or carbon. The functionof the heating layer is to absorb the laser radiation and convert theradiation into heat.

Suitable metals include transition metals and metallic elements ofGroups IIIa, IVa, Va, VIa, VIII, IIIb, and Vb, their alloys with eachother, and their alloys with the elements of Groups Ia and IIa.Preferred metals include Al, Cr, Sb, Ti, Bi, Zr, TiO2, Ni, In, Zn, andtheir alloys; carbon is also preferred. More preferred are Al, Ni, Cr,Zr and C. Most preferred are Al, Ni, Cr, and Zr.

The heating layer preferably consists essentially of one materialapplied in a single layer. However, it is acceptable in the practice ofthe present invention to make up the heating layer by successivedeposition of more than one suitable material to form a multi-layerstructure. The thickness of the heating layer is generally about 2nanometers to 100 nanometers, preferably about 5 to 10 nanometers.

Transfer Layer

The transfer layer (3) lies at the heart of the present invention. Thetransfer layer of the present invention comprises (a) two or morepolymeric binders at least one pair of which said binders differ inglass transition temperature (T_(g)) by at least 20 centigrade degrees,and (b) an imageable component. Preferably the binders differ in T_(g)by at least 40 centigrade degrees. Most preferably the binders differ inT_(g) by at least 80 centigrade degrees.

The higher T_(g) binder of the pair exhibits a T_(g) of between 20 and140 centigrade degrees higher than the T_(g) of the lower T_(g) binderin the pair. The T_(g) of the higher T_(g) binder in the pair rangesfrom 70° C. to 140° C. The T_(g) of the lower T_(g) binder of the pairranges from −40° C. to 60° C. Preferably the T_(g) of the higher T_(g)binder of the pair ranges from 100° C. to 140° C. Preferably the T_(g)of the lower T_(g) binder of the pair ranges from −40° C. to 0° C.

The polymeric binder suitable for use in the present inventionpreferably does not self-oxidize, decompose or degrade at thetemperatures to which it exposed during the laser exposure so that theimageable component and binder are transferred with little or nodegradation. Binder polymers suitable for use as the high T_(g)component of the pair include, but are not limited to, polystyrene andcopolymers thereof, acrylates, methacrylates and co-polymers thereof.Binder polymers suitable for use as the low T_(g) component of the pairinclude but are not limited to butyl acrylates and co-polymers thereof.The monomer units present in the polymeric binders suitable for use inthe present invention may be substituted or unsubstituted. Mixtures ofpolymers can also be used.

In a preferred embodiment, 1-5 mol-% of a crosslinkable monomer isincorporated into the polymeric binders of the instant invention. Aftercross-linking, the binders exhibit resistance to the temperatures andsolvents employed in the formation of color filter arrays in liquidcrystal display devices, making this embodiment highly preferred in thatapplication. Suitable crosslinkable comonomers include but are notlimited to hydroxy ethyl methacrylate and glycidyl methacrylate.

The polymeric binders suitable for use in the present invention arepresent at a concentration of about 15-50% by weight, preferably 30-40%by weight, based on the total weight of the transfer layer. The weightratio of higher T_(g) binder to lower T_(g) binder should be in therange of 60:40 to 95:5, preferably in the range of 75:25 to 92:8.

The binders suitable for use in the present invention are synthesizedpreferably in the form of latex dispersions, as described in Mazur etal, U.S. Pat. No. 6,020,416, incorporated herein by reference to theentirety, and as hereinbelow exemplified. The synthesis of polymerlatexes is a very well-known art in widespread commercial use.

In a preferred embodiment, one or more of the polymeric binders comprisemonomer units having pendant groups which are capable of undergoingfree-radical induced or cationic crosslinking reactions. Pendant groupswhich are capable of undergoing free-radical induced crosslinkingreactions are generally those which contain sites of ethylenicunsaturation, such as mono- and polyunsaturated alkyl groups; acrylicand methacrylic acids and esters. In some cases, the pendantcrosslinking group can be photosensitive, as is the case with pendantcinnamoyl or N-alkyl stilbazolium groups. Pendant groups which arecapable of undergoing cationic crosslinking reactions includesubstituted and unsubstituted epoxide and aziridine groups.

Crosslinkable binders suitable for the practice of the invention can beformed by direct copolymerization of one or more ethylenicallyunsaturated dicarboxylic acid anhydrides, or the corresponding alkyldiesters, with one or more of the above comonomers. Suitableethylenically unsaturated dicarboxylic acid anhydrides are, for example,maleic anhydride, itaconic acid anhydride and citraconic acid anhydrideand alkyl diesters such as the diisobutyl ester of maleic anhydride. Thecopolymer binder containing acid anhydride functionality can be reactedwith primary aliphatic or aromatic amines.

For color imaging applications, such as color proofing or color filterarray formation, the imageable component will comprise a colorant. Thecolorant can be a pigment or a non-sublimable dye. It is preferred touse a pigment as the colorant for stability and for color density, andalso for the high decomposition temperature. Examples of suitableinorganic pigments include carbon black and graphite. Examples ofsuitable organic pigments include Rubine F6B (C.I. No. Pigment 184);Cromophthal® Yellow 3G (C.I. No. Pigment Yellow 93); Hostaperm® Yellow3G (C.I. No. Pigment Yellow 154); Monastral® Violet R (C.I. No. PigmentViolet 19); 2,9-dimethylquinacridone (C.I. No. Pigment Red 122);Indofast® Brilliant Scarlet R6300 (C.I. No. Pigment Red 123); QuindoMagenta RV 6803; Monastral® Blue G (C.I. No. Pigment Blue 15);Monastral® Blue BT 383D (C.I. No. Pigment Blue 15); Monastral® Blue G BT284D (C.I. No. Pigment Blue 15); and Monastral® Green GT 751D (C.I. No.Pigment Green 7). Combinations of pigments and/or dyes can also be used.

For color filter array applications, the imageable component ispreferably a high transparency pigment through which ca. 80% of incidentlight energy passes through unabsorbed, and having a latex particle sizeof ca. 100 nanometers.

In accordance with principles well known to those skilled in the art,the concentration of colorant will be chosen to achieve the opticaldensity desired in the final image. The amount of colorant will dependon the thickness of the active coating and the absorption of thecolorant. Optical densities greater than 1.3 are typically required.Even higher densities are preferred. Optical densities in the 2-3 rangeor higher are achievable with application of this invention.

A dispersant is usually present when a pigment is to be transferred, inorder to achieve maximum color strength, transparency and gloss. Thedispersant is generally an organic polymeric compound and is used toseparate the fine pigment particles and avoid flocculation andagglomeration. A wide range of dispersants is commercially available. Adispersant will be selected according to the characteristics of thepigment surface and other components in the composition as practiced bythose skilled in the art. One suitable type of dispersant is describedin “Use of AB Block Polymers as Dispersants for Non-aqueous CoatingSystems”, by H. C. Jakubauskas, Journal of Coating Technology, Vol. 58,No. 736, pages 71-82. Suitable AB dispersants are disclosed in U.K.Patent 1,339,930 and U.S. Pat. Nos. 3,684,771; 3,788,996; 4,070,388;4,912,019; and 4,032,698. Conventional pigment dispersing techniques,such as ball milling, sand milling, etc., can be employed. For colorfilter applications, the binder polymers of the transfer layer can insome cases also act as dispersants for the pigment.

For lithographic applications, the imageable component is an oleophilic,ink-receptive material. The oleophilic material is usually afilm-forming polymeric material and may be the same as the binder.Examples of suitable oleophilic materials include polymers andcopolymers of acrylates and methacrylates; polyolefins; polyurethanes;polyesters; polyaramids; epoxy resins; novolak resins; and combinationsthereof. Preferred oleophilic materials are acrylic polymers. Inlithographic applications, a colorant can also be present in thetransfer layer. The colorant facilitates inspection of the plate afterit is made. Any colorants suitable for use in the invention may beemployed.

For photomask applications, a dye, generally a black dye and/or pigmentsuch as carbon black or other dark material is present in the transferlayer as the imageable component. The imageable component(s) forphotomask applications are chosen such that optical densities on thereceiver element in areas where material has been transferred arepreferably at least 2.0 and more preferably are about 3.0 or higher.

In general, for color proofing, photomask, and lithographic printingapplications, the imageable component is present in an amount of fromabout 25 to 95% by weight, based on the total weight of the transfercoating. For color proofing applications, the amount of imageablecomponent is preferably 35-65% by weight; for lithographic printingapplications, preferably 65-85% by weight.

The color filter array to be used in fabrication of a liquid crystaldisplay device may have to withstand exposure to solvents and heat.

For color filter applications, a dye and/or pigment is present in thetransfer layer as the imageable component. The imageable component(s)for color filter applications are chosen such that optical densities onthe receiver element in areas where material has been transferred arepreferably between 1.0 and 2.0 for red, blue and green, and between 3.0and 4.0 for black. In general, the imageable component is present in anamount of from about 20 to 80% by weight, preferably 30 to 50% byweight, based on the total weight of the transfer coating.

Other materials can be present as additives in the transfer layer aslong as they do not interfere with the essential function of the layer.Examples of such additives include coating aids, plasticizers, flowadditives, slip agents, antihalation agents, antistatic agents,surfactants, and others which are known to be used in the formulation ofcoatings. However, it is preferred to minimize the amount of additionalmaterials in this layer, as they may deleteriously affect the finalproduct after transfer. Additives may add unwanted color for colorproofing applications, or they may decrease durability and print life inlithographic printing applications.

The transfer layer generally has a thickness in the range of about 0.1to 5 micrometers, preferably in the range of about 0.1 to 1.5micrometers. Thicknesses greater than about 5 micrometers are generallynot preferred as they require excessive energy in order to beeffectively transferred to the receiver.

Although it is preferred to have a single transfer layer, it is alsopossible to have more than one transfer layer, and the different layerscan have the same or different compositions, as long as they allfunction as described above. The total thickness of the combinedtransfer layers should be in the range given above.

The transfer layer(s) can be coated onto the heating layer of the donoror on a temporary support as a dispersion in a suitable solvent,however, it is preferred to coat the layer(s) from a solution usingconventional coating techniques or printing techniques, for example,gravure printing. Any suitable solvent can be used as a coating solvent,as long as it does not deleteriously affect the properties of theassemblage.

A laser-absorbing dye may be incorporated into the donor layer as athermal amplification additive. The function of such an additive is toabsorb the incident radiation and convert it into heat, leading to moreefficient heating. It is preferred that the dye absorb in the infraredregion. For imaging applications, it is also preferred that the dye havevery low absorption in the visible region. Examples of suitable infraredabsorbing dyes which can be used alone or in combination includepoly(substituted) phthalocyanine compounds and metal-containingphthalocyanine compounds; cyanine dyes; squarylium dyes;chalcogenopyryioacrylidene dyes; croconium dyes; metal thiolate dyes;bis(chalcogenopyrylo) polymethine dyes; oxyindolizine dyes;bis(aminoaryl) polymethine dyes; merocyanine dyes; and quinoid dyes.

Infrared absorbing materials disclosed in U.S. Pat. Nos. 4,778,128;4,942,141; 4,948,778; 4,950,639; 5,019,549; 4,948,776; 4,948,777 and4,952,552 may also be employed as thermal amplification additives.

The weight percentage of the thermal amplification additive, versus, forexample, the total solid weight composition of the donor layer may rangefrom 0-20%. When present in the transfer coating, the thermalamplification weight percentage is generally at a level of 0.95-11.5%.The percentage can range up to 25% of the total weight percentage in thetransfer coating. These percentages are non-limiting and one of ordinaryskill in the art can vary them depending upon the particular compositionof the donor layer.

Receiver Element

The receiver element is the part of the laserable assemblage to whichthe imageable component and polymeric binders, that is, the transferlayer, are transferred. In most instances effective transfer requiresthe donor and receiver elements to be in direct physical contactthroughout the imaged area.

The receiver element may consist of a single layer, or a multi-layerelement. There is no particular limitation on the materials suitable foremployment in the receiver except that it be capable of retaining thetransferred image and that it be dimensionally stable. Suitablematerials include PET, polyether sulfone, polyimide, poly(vinylalcohol-co-acetal), polyethylene, cellulose ester, such as celluloseacetate. The materials may be in various forms including continuouspolymeric films or sheets, or in the form of spun-bonded sheets such asTyvek® spun-bonded polyolefin. The polymer so employed may containopacifying fillers if so desired. The particular selection of receiverelement materials will depend upon the exigencies of the particularapplication for the laserable assemblage of the invention. For example,paper-like supports are preferred for proofing applications, whilepoly(ethylene terephthalate) is preferred for medical hardcopy and colorfilter array applications. For color filter applications, the receiverelement can also include receptor elements such as a flexible glassstubstrate optionally with an image-receiving layer.

In another embodiment, suitable for use in photomask applications, thereceiver element comprises photosensitive materials, especiallyphotohardenable materials, such as are well-known in the art.

As is shown in FIG. 3A, the receiver element preferably has animage-receiving layer (4) on one surface of the support layer (5). Theimage-receiving layer (4) can be a coating of, for example,polycarbonate; polyurethane; polyester; polyvinyl chloride;styrene/acrylonitrile copolymer; poly(caprolactone); vinylacetatecopolymers with ethylene and/or vinyl chloride; (meth)acrylatehomopolymers (such as butyl-methacrylate) and copolymers; and mixturesthereof. This image-receiving layer can be present in any amounteffective for the intended purpose. In general, good results have beenobtained at coating weights of 1 to 5 microns.

In a preferred embodiment of the present invention the laserableassemblage of the invention is employed for fabrication of color filterarrays. In this and other embodiments, laser imaging is followed by oneor more transfer steps by which the image layer on the receiving elementis transferred to a final support, such as a flexible glass sheet,suitable for incorporation into a liquid crystal display. In such anembodiment, it is highly preferred to include a release layer betweenthe support layer and the image-receiving layer of the receivingelement. Suitable for use as the release layer are polyamides,silicones, vinyl chloride polymers and copolymers, vinyl acetatepolymers and copolymers, and plasticized polyvinyl alcohols. The releaselayer can have a thickness in the range of 1 to 50 microns.

In a more preferred embodiment, a deformable layer is also present inthe receiving layer, generally disposed between the release layer andthe receiver support. The deformable layer serves to improve theintimacy of contact between the receiver element and the donor elementwhen assembled. Examples of suitable materials for use as the deformablelayer include copolymers of styrene and olefin monomers such asstyrene/ethylene/butylene/styrene, styrene/butylene/styrene blockcopolymers, and other elastomers useful as binders in flexographic plateapplications.

In the most preferred embodiment of the present invention, the receivingelement comprises at least one crosslinkable binder in theimage-receiving layer.

Various types of lasers can be used to expose the laserable assemblage.The laser is preferably one emitting in the infrared, near-infrared orvisible region. Particularly advantageous are diode lasers emitting inthe region of 750 to 870 nm which offer a substantial advantage in termsof their small size, low cost, stability, reliability, ruggedness andease of modulation. Diode lasers emitting in the range of 780 to 850 nmare most preferred. Laser fluence about 400 mJ/cm2, is suitable for thepractice of the invention. Excesssive fluence should be avoided to limitdegradation of the transfer layer. Suitable lasers are available from,for example, Spectra Diode Laboratories (San Jose, Calif.).

The laserable assemblage is exposed imagewise so that material, i.e.,the crosslinkable binders and the imageable component, is transferred tothe receiver element in a pattern. The pattern itself can be, forexample, in the form of dots or line work generated by a computer suchas a digitized image taken from original artwork. The laser beam and thelaserable assemblage are in constant motion with respect to each other,such that each minute area or pixel of the assemblage is individuallyaddressed by the laser. This is generally accomplished by mounting thelaserable assemblage on a rotatable drum. A flat bed recorder can alsobe used.

For donor elements of this invention that are used to make a photomaskon a photosensitive element for subsequent use in making a relief image,the material transferred from the donor to the receiver and whichbecomes a mask area, or, alternatively, in other embodiments thematerial remaining on the donor as a mask area should be “substantiallyopaque to actinic radiation”. The term “substantially opaque to actinicradiation” means that the amount of actinic radiation transmitted to theunderlying photosensitive layer or photohardenable layer is so minisculethat no significant amount of photoinduced reaction occurs in thephotosensitive or photohardenable layer. The material of the donorelement may be transferred to the coversheet or the barrier layer or thephotohardenable layer of the photosensitive receiver element.

After exposure, the donor and receiver elements are normally, though notnecessarily, separated. Separation can be achieved using anyconventional separation technique and can be manual or automatic.

While it is normally the imaged receiver element which is employed inone or another application, it is also possible for the intended productof laser imaging to be the donor element after laser exposure. Forexample, if the donor support is transparent, the donor element can beused as a phototool for conventional analog exposure of photosensitivematerials, e.g., photoresists, photopolymer printing plates,photosensitive proofing materials, medical hard copies, and the like.

In proofing and color filter array applications, the receiver elementcan be an intermediate element onto which a multicolor image is builtup. A donor element having a first imageable component in the transferlayer is exposed and separated as described above. The receiver elementhas an image formed with the first imageable component. Thereafter, asecond donor element having an imageable component in the transfer layerdifferent from that of the first donor element forms a laserableassemblage with the receiver element having the image of the firstimageable component and is imagewise exposed and separated as describedabove. The color image on the receiver element can then be transferredfor example by lamination to a permanent substrate, such as paper forproofing applications, or to a flexible glass substrate or polarizingfilter element of an LCD device for color filter array applications.After laminating the receiver element intermediate to the permanentsubstrate and removing the receiver element substrate, theimage-receiving layer may remain with the transfer layer thus laminated.The image-receiving layer can then act as a planarizing layer to providea substantially planar layer on the outer surface of the LCD device andthereby obscure any nonuniformities in the thickness of the color filterlayer.

For the embodiments of this invention that involve fabrication of aphotomask on a photosensitive element and subsequent use of thephotomask to create a relief image such additional processing steps asare known in the art will be required, including imagewise exposure ofthe photosensitive followed by development according to the methods ofthe art thus creating a relief image.

In those embodiments of the invention in which the polymeric binderscomprise crosslinkable elements, particularly in the most preferredembodiment wherein the imaged laserable assemblage will be employed inthe fabrication of color filter arrays, it is preferred to follow theimage transfer by laser irradiation by a cross-linking step. When thereceiver element of the laserable assemblage of the invention isemployed as an intermediate element which is laminated to a permanentsubstrate such as a flexible glass substrate, it is found convenient inthe practice of the invention to effect the cross-linking by heating thereceiver element to a temperature at which the free-radical initiator isactivated while simultaneously effecting the lamination. Temperatures of100-140° C. are typical.

EXAMPLES Synthesis of Binder Polymers

T_(g) (Glass transition temperature) values reported are mid-pointtemperatures in degrees Centigrade from DSC scans recorded according toASTM D3418-82.

Molecular weights were measured by gel permeation chromatography (GPC).The equipment used consisted of the following: Columns, 2-5 μm×300mm×7.5 mm (Poly Lab part # 1110,6500); Detector, Waters (Waters, Inc.,Milford, Mass.) 410 Refractive Index detector; Pump, Waters 590; andWaters column heater. Conditions used were: Refractive Index detectorinternal temperature, 30° C.; Column heater temperature, 30° C.; THFsolvent, 0.025% BHT inhibited (from Omnisolv, part # TX0282,1 distilledLC grade); Flow rate, 1 ml/min; Concentration, 0.1% (10 mg/10 ml).Samples were prepared by dissolving parts of the samples used for solidsdetermination overnight with gentle shaking, and then filtering through0.5 μm filter (Millipore, Bedford, Mass., part # SLSR025NB).

Dynamic light scattering was performed using Brookhaven InstrumentBI-9000AT digital correlator (Brookhaven Instruments, Brookhaven, N.Y.).An argon-ion laser with wavelength 488 nm and power 200 mW was used.Measurements were made at room temperature with scattering angle 60°.The samples were diluted 200 uL into 20 mL water then again 100 uL into20 mL water, then filtered with 0.45 micron filter. The results arereported as diameter (particle size) in nm units. For generaldiscussions of the determination of particle sizes by quasielastic lightscattering, see Paint and Surface Coatings: Theory and Practice, ed. ByR. Lombourne, Ellis Horwood Ltd., West Sussex, England, 1987, pp.296-299, and The Application of Laser Light Scattering to the Study ofBiological Motion, ed. By J. C. Earnshaw and M. W. Steer, Plenum Press,New York, 1983, pp. 53-76.

A 3-L, round bottom flask was equipped with a condenser, additionfunnel, mechanical stirrer, and temperature controller probe.Polymerizations were carried out under a nitrogen atmosphere in theflask.

Monomers and initiators were commercially available (Aldrich ChemicalCo., Milwaukee, Wis.) and used as received. Ammonium lauryl sulfate wasPolystep B-7, a 29% solution in deionized water, available from StepanCo., Northfield, Ill.

TABLE 1 Polymer 1 (P1) Ingredients for Synthesis of Polymer 1. Reagent MWeight Moles Grams Ammonium Lauryl Sulfate 283.00 0.0068 6.90 AmmoniumPersulfate 228.20 0.0009 0.2 Methyl Methacrylate 100.12 0.1998 20Glycidyl Methacrylate 142.15 0.0563 8 Butyl Acrylate 128.17 0.0000 320Styrene 104.15 0.3841 40 Methacrylic Acid 86.09 0.1394 12

The materials shown in Table 1 were employed in the quantities shown.

700 mL of water and the ammonium lauryl sulfate were charged to theflask, which was stirred and heated to 85° C. The ammonium persulfatewas dissolved in 100 mL water, and 80 mL of this persulfate solution wasadded to the flask. Half of the monomers, except for the methacrylicacid, were mixed and charged to the addition funnel, and about 20 mL wasadded immediately to the flask. After a few minutes, the remainder inthe funnel was added, dropwise, over a time period of about 1 hour,while the temperature in the flask was held between 85 and 90° C. Theremaining monomers, including the methacrylic acid, were mixed, added tothe addition funnel, and added to the reaction over an additional timeperiod of 1 hour, still keeping the temperature in the flask between 85and 90° C. After the addition was finished, the remaining persulfatesolution was added, and the reaction was heated to 85° C. cooled to 60°C., and filtered through paint strainers into plastic bottles.

Solids content was measured by putting about 5 grams of latex in atared, 5-cm aluminum pan, which was placed in a 75° C. vacuum oven atabout 400 mm Hg vacuum for 1 to 2 days. Physical properties are shown inTable 3.

Polymers 2-7 (P2-P7)

Polymers 2-7 were prepared in a manner identical to that of Polymer 1 inboth materials and conditions, but with different amounts of thosematerials. The various composition employed are shown in Table 3.

Polymer 8 (P8)

Polymer 8 was prepare in the same manner as Polymers 1-7, but withsomewhat different ingredients, shown in Table 2. In contrast withPolymers 1-7, no butyl acrylate was employed, but a plasticizer wasadded. The plasticizer was a 3:1 Caprolactone/1,4-Cyclohexanedimethanoladduct prepared as described in U.S. Pat. No. 5,159,047.

TABLE 2 Ingredients for Synthesis of Polymer 8. Reagent M Weight MolesGrams Ammonium Lauryl Sulfate 283.00 0.0068 6.90 Ammonium Persulfate228.20 0.0009 0.2 Methyl Methacrylate 100.12 1.7979 180 GlycidylMethacrylate 142.15 0.0563 8 Styrene 104.15 1.9203 200 Methacrylic Acid86.09 0.1394 12 Plasticizer 100

700 mL of water and the ammonium lauryl sulfate were charged to theflask, which was stirred and heated to 85° C. The ammonium persulfatewas dissolved in 100 mL water, and 80 mL of this persulfate solution wasadded to the flask. Half of the monomers, except for the methacrylicacid, and half of the plasticizer, were mixed and charged to theaddition funnel, and about 20 mL was immediately added to the flask.After a few minutes, the remainder was added, dropwise, over a timeperiod of about 1 hour while the temperature in the flask was heldbetween 85 and 90° C. The remaining monomers and plasticizer were mixed,added to the addition funnel, and added to the reaction over 1 hour,keeping the temperature in flask between 85 and 90° C. After theaddition was finished, the remaining persulfate solution was added, andthe reaction was heated to 85° C., cooled to 60° C., and filteredthrough paint strainers into plastic bottles.

TABLE 3 Analytical Data and compositions for Polymer Latexes % % % % %Particle Mn/ Mw/ Polymer % MMA BA MAA GMA STY Solids Size Tg 1000 1000P1 5 80 3 2 10 32.7 83.1 −21 96 319 P2 95 0 3 2 0 33.5 79.5 130 P3 15 803 2 0 33.4 91.4 −27 P4 85 0 3 2 10 33.4 77.7 126 P5 45 0 3 2 50 33.380.8 113 P6 70 0 3 2 25 33.4 81.4 121 P7 34 12 3 1 50 33 92 87 40 388 P845 0 3 2 50 38.0 84.2 63 122 487

Formation of Laserable Assemblages

The following examples demonstrate the steps as shown in FIGS. 3A-G informing a color filter array of the invention. The donors and receiverscomprised polymers with crosslinkable functional groups. The receiverfurther comprised a crosslinkable organic layer coated on a substratethat upon lamination of the patterned color layer to glass actedeffectively as a planarizing layer.

In FIG. 3A, the transfer layer (3) of the donor element was imaged byfocusing an infrared beam onto the metal layer (2) positioned betweenthe substrate (1) and the transfer layer (3). The heat from the metallayer (2) transferred the imaged portions of the transfer layer (3) ontothe image receiving layer (4) of the receiver element. Imaging wasperformed using a Spectrum Trendsetter exposure unit (Creo Inc.Vancouver, Canada). The system consisted of an 81.2-cm long drum 91-cmin perimeter. The donor and receiver elements were independently loadedinto the machine, the donor element being slightly larger in size thanthe receiver element. Their respective positions on the rotating drumand contact between the elements were maintained by the application ofvacuum.

The donor element was exposed with an array of 240 overlapping 5×2micron spots that result from the splitting through a light valve of thelaser beam from a 20 watt infrared diode laser emitting at 830 nm in 1microsecond pulses. The drum speed was varied from 60 to 170 RPM thatprovided incident energy densities ranging from 125 to 550 mJ/cm2. Thedonor and receiver elements were then separated wherein an image (6) wasformed on the image receiving layer of the receiver element.Alternately, the imaging steps were repeated at least once with donorelements having a transfer layer comprising a different pigmentdispersion.

The receiver element comprising a single or multicolor image on theimage receiving layer (4) was laminated to glass treated with anadhesion promotor, and the receiver support (Melinex® 574 PET) waspeeled off. This resulted in a color filter comprised of glass treatedwith an adhesion promoter, a color filter pattern and the imagereceiving layer (4) on top that may function as a planarizing layer.Both the transferred color image and the image receiving layer werethermally crosslinkable.

The color filter donor films comprised a three layer structure: 1) adonor support (for example Melinex® 574 backing), 2) a thin sputteredmetal layer (2), and 3) a 1 micron thick pigmented layer of theformulation in each specific example which had been rod coated onto thesputtered metal layer. The image receiving layer of the formulationslisted below was coated to 1 micron in thickness onto a 4-mil Melinex®574 (available from DuPont) receiver support.

In each specimen, the pigmented transfer layer on the donor elementcomprised at least two of the polymeric binders P1-P8, the low T_(g)component selected from P1 or P3, and the high T_(g) component selectedfrom P2, P4, P5, P6, P7 or P8. In addition binders usable in colorfilter compositions are preferably crosslinkable since they are exposedto a variety of solvents in the building of the face plate for an LCDdisplay.

All temperatures throughout the specification are in ° C. (degreesCentigrade) and all percentages are weight percentages unless indicatedotherwise.

Examples 1-4

The formulations in the following examples illustrate the ability tocontrol quality of the transferred image as a function of the styrenecontent in the high T_(g) binder. The samples comprise two binders; withhigh and low T_(g) at a concentration ratio of 85 to 15% respectively.Images that transferred without heat induced decomposition show a highdegree of gloss and thus high optical density. In contrast, when theheat generated during transfer leads to the decomposition of the binderthe transfer material exhibits reduced gloss and optical density. Inorder to effect cross-linking after transfer, it is particularlyimportant that the binders be transferred with minimal degradation.Black films, are particularly susceptible to degradation. Degradationwas reduced by incorporation of styrene comonomers in the polymericbinders.

The donor element was fabricated by sputter coating an 8 nm thickness ofmetallic chromium, having 40% optical transmission onto a 102 μm thickMelinex® 574 base. Metal thickness was monitored in situ using a quartzcrystal and after deposition by measuring optical frequency reflectionand transmission of the deposited films. The black-pigmented transferlayer comprised a black pigment dispersion having a pigment todispersant (p/d) ratio of 2 incorporated into the compositions specifiedin Table 4. The pigmented layer was deposited upon the metallic layer bycoating using a Waterproof®CV coater available from the DuPont Company,Wilmington, Del., equipped with a #6 Meyer rod. The film was dried at45° C. for 5 minutes. The thickness of the pigmented layer was 1.0 μm.PEG300 and PEG6800 were oligomeric polyethylene glycol plasticizers.Zonyl® FSA was a fluorinated surfactant available from the DuPontCompany. The percentage of low T_(g) binder in the composition isexpressed as a percentage of the total weight of binder in the transferlayer.

TABLE 4 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ingredient % styrene % (g) % (g) % (g) %(g) Black 60.000 12.000 60.000 12.000 60.000 12.000 60.000 12.000Pigment Dispersion p/d 2 P2 0 32.300 2.9400 P4 10 32.300 2.9400 P6 2532.300 2.9400 P5 50 32.300 2.9400 P3 5.7000 0.5200 5.7000 0.5200 5.70000.5200 5.7000 0.5200 PEG 300 2.0000 0.0600 2.0000 0.0600 2.0000 0.06002.0000 0.0600 Zonyl ® FSA 0.0400 0.0400 0.0400 0.0400 H₂O 4.4400 4.44004.4400 4.4400 % Low T_(g) 15% 15% 15% 15% solids 15% 3 15% 3 15% 3 15% 3

The optical densities listed in Table 5 below represent the density ofthe pigment transfered onto a receiver at the specified drum speed (andtherefore, sensitivity). Densities were measured in transmission using aMacBeth reflection densitometer (Newburgh, N.Y.).

TABLE 5 Optical Density Drum Speed (rpm) Ex. 1 Ex. 2 Ex. 3 Ex. 4 1002.14 2.2 2.19 3.23 110 2.1 2.03 2.03 3.21 120 2.13 2.06 3.34 3.67 1302.28 2.03 3.59 3.68 140 2.81 3.01 3.67 3.68 150 3.2 3.45 3.69 3.69 1603.3 3.41 3.66 3.67 170 3.32 3.45 3.65 3.61 180 3.37 3.52 3.63 3.49 1903.46 3.43 3.63 3.61 100 3.42 3.48 3.48 3.58

Examples 5-8

In Examples 5-8, the optical density of the transferred film atdifferent transfer speeds was used as an indication of the thermalstability of the transferred layer. Higher gloss and optical densitywere indicators of higher thermal stability during transfer.

The specimens were prepared using the methods and materials described inExamples 1-4. The thickness of the pigmented layer was 10 μm.Compositions are shown in Table 6.

TABLE 6 Ex. 5 Ex. 6 Ex. 7 Ex. 8 % styrene % (g) % (g) % (g) % (g) Black60.000 12.000 60.000 12.000 60.000 12.000 60.000 12.000 Pigment p/d 2 P20 32.3000 2.9400 P4 10 32.300 2.9400 P6 25 32.300 2.9400 P5 50 32.3002.9400 PEG 6800 5.7000 0.5200 5.7000 0.5200 5.7000 0.5200 5.7000 0.5200PEG 300 2.0000 0.0600 2.0000 0.0600 2.0000 0.0600 2.0000 0.0600 Zonyl ®FSA 0.0400 0.0400 0.0400 0.0400 H2O 4.3900 4.3900 4.3900 4.3900 % Low Tg 15%  15%  15%  15% Solids  15% 3  15% 3  15% 3  15% 3 TOTAL 100% 20.000100% 20.000 100% 20.000 100% 20.000

The optical densities in Table 7 below represent the optical density ofthe black pigment layer transferred onto a receiver sheet at thespecified drum speed (and therefore, sensitivity). Densities weremeasured using a McBeth reflection densitometer (Newburgh, N.Y.).

TABLE 7 DS Ex. 5 Ex. 6 Ex. 7 Ex. 8 100 1.09 1.96 2.2 1.08 110 1.95 2.242.13 2.06 120 2.08 2.31 2.19 2.2 130 2.13 2.28 2.49 3.23 140 2.2 2.422.61 3.45 150 2.3 2.3 3.38 3.42 160 2.24 2.23 3.35 3.43 170 2.32 2.463.52 3.3 180 2.55 2.51 3.45 3.48 190 2.77 2.91 3.43 3.52 100 3.43 3.613.43 3.32

Examples 9-11

In Examples 9-11, the binder polymers were crosslinkable, and uponlamination on to glass, the receiver layer became the planarizing layerfor a color filter. The heating layer and substrate were the same as inExamples 5-8. The pigmented transfer layers were coated using commercialcoating equipment to 63 cm width and 1 μm in thickness. Compositions areshown in Table 8.

As shown in FIG. 3, the laserable assemblage comprising the donorelement and the receiver element is exposed through the donor element inselected areas by radiation in the form of heat or light, e.g. a laser.If the transfer layer (3) of the donor element is red, then a red image(6) is transferred to the image receiving layer (4) of the receiverelement. After exposure, the donor element is separated from thereceiver element.

The transfer step can be repeated with the same receiver element bearingthe first image (6) and one or more different donor elements having acolorant of a different color, e.g. blue or green, to prepare amulticolor color filter pattern comprising for example a red image (6),a blue image (7) and a green image (8). If the receiver support is thepermanent substrate, e.g. glass, this forms a color filter. Alternately,as shown in FIG. 3, the multicolor image, comprising for example green,blue and red, may be laminated to the permanent substrate, e.g. glass,and the receiver support layer (5) is peeled off to form a color filter.

The receiver backing (5) consists of a Melinex® 574 polyester base,coated with the crosslinkable composition specified in Table 8b to athickness of 1 micron (4). In FIG. 3, (2) designates a thin layer ofmetal. (3) is a donor coating.

The images were produced as previously described using the spectrumTrendsetter. After the patterning of the first color was completed onthe receiver (6), the first donor was unloaded and the second donor wasautomatically loaded onto the receiver. After the patterning of thesecond color was completed (7) the procedure was repeated withsequential colors (8). After all colors were completed the receiver wasunloaded and laminated onto glass (10) onto which an adhesive was spincoated (9) and the backing of the receiver (5) was removed.

The color filter on glass shown in FIG. 4 below was produced followingthe procedure previously described. The specific red, blue, green (Table8a) and crosslinkable receiver formulations (Table 8b) are included. Thelamination was performed at 120° C. on a flat press.

TABLE 8a Donor Compostions Red Green Blue % Weight % Weight % WeightMaterial Solids (g) Solids (g) Solids (g) PEG-300 — — 1.98% 0.148 — —SDA-4927  2.00% 0.150 1.48% 0.111 2.00% 0.150 Zonyl ®   0.50% 0.0381.25% 0.094 0.50% 0.038 FSA Red 60.06% 30.030 — — — — Pigment dispersionGreen — — 59.25%  29.626 — — Pigment Dispersion Blue — — — — 60.00% 30.000 Pigment Dispersion p/d = 4 P1  3.70% 0.841 5.41% 1.230 7.50%1.705 P5 33.74% 7.668 30.63%  6.962 30.00%  6.818 — 11.274 — 11.830 —11.290 15.00% 15.00% 15.00%   100% 50.00  100% 50.00  100% 50.00

TABLE 8b Receiver Composition 10.5% solids Receiver Sol'n % Ctg % Water(distilled) 62.0 Zonyl FSA (25% 0.4 1.0 in IPA/Water) Butyl Cellosolve6.0 Acrylic Latex 22.1 69.3 RCP24692 High Tg (33%, in water) AcrylicLatex 9.5 29.7 RCP26061 Low Tg (33%, in water)

Examples 12-16

The formulations in the following examples illustrate the ability tocontrol line edge resolution of the transferred material as a functionof the low T_(g) to high T_(g) binder ratio. That is, in Table 10 beloweach blue formulation comprises two binders; with high and low glasstransition temperatures and the ratio of the low ratio was varied from10 to 20% of the total binder content. The donor film was fabricated asin Examples 5-8. The blue pigmented layers of the formulation specifiedin Table 9 were coated using a Waterproof®CV coater (DuPont) with a #6Meyer rod. The film was dried at 45° C. for 5 minutes. The thickness ofthe pigmented layer was 1.0 μm.

TABLE 9 ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 % (g) % (g) % (g) % (g) % gBlue Pigment 60.0000 30.000 60.000 30.000 60.000 40.000 60.000 12.00060.000 30.000 Dispersion P7 29.600 6.7300 30.525 6.9400 31.450 7.150032.275 7.3600 33.300 7.5700 P1 7.4000 1.6800 6.4750 1.4700 5.5500 1.26004.6250 1.0500 3.7000 0.8400 SDA 2.5000 0.1875 2.5000 0.1875 2.50000.1875 2.5000 0.1875 2.5000 0.1875 Zonyl ® FSA 0.5000 0.0375 0.50000.0375 0.5000 0.0375 0.5000 0.0375 0.5000 0.0375 H2O 11.365 11.36511.365 11.365 11.365 % Low Tg 20.00% 17.50 15.0% 12.5% 10.0% Solids  15% 7.5 15% 7.5   15% 7.5   15% 7.5 0.1000 7.5000 TOTAL 50.000 50.00050.000 50.000 50.000

FIGS. 5 and 6 illustrate the effect of binder ratio on line edgeresolution as obtained in Examples 12 and 16 respectively.

Examples 17-19

In the formulations in the following examples the presence of thecaprolactone plasticizer in the latex allowed for high resolution withimproved adhesion upon transfer even after raising the glass transitionof the high T_(g) latex from 80° C. (ex 12-16) to 118° C. for theseexamples. In these examples the ratio of low T_(g) binder was variedfrom 8 to 10%. Table 10 below shows blue formulations comprising twobinders; with high (118° C.) and low glass transition temperatures (−22°C.). The donor element was fabricated according to the method employedin Examples 12-16.

TABLE 10 ex. 17 Ex. 18 Ex. 19 % (g) % (g) % (g) Blue 60.0000 30.000060.0000 30.0000 60.0000 40.0000 Pigment Dispersion P5 29.1200 6.620030.5250 6.9400 31.4500 7.1500 P1 2.8800 0.6500 6.4750 1.4700 5.55001.2600 P8 5 0.97 SDA 2.5000 0.1875 2.5000 0.1875 2.5000 0.1875 Zonyl ®FSA 0.5000 0.0375 0.5000 0.0375 0.5000 0.0375 H2O 11.5350 11.365011.3650 Plasticizer 1.00% 1.00%  1.00% % Low Tg 8.00% 9.00% 10.00%Solids   15% 7.5   15% 7.5   15% 7.5 TOTAL 50.0000 50.0000 50.0000

Examples 20-23

In the formulations of these different levels of plasticizer in thelatex allowed for adjusting the adhesion of the transfer layer to thereceiver.

The donor film comprisd a Cr heating layer 8 nm in thickness andcharacterized by 40% transmission sputter coated onto a 4 mil Melinex®574 base. The metal thickness, sputtered at Vacuum Deposit Inc.(Louisville, K.Y.), was monitored in situ using a quartz crystal andafter deposition by measuring reflection and transmission of the films.The red pigmented layers of the formulations specified in the tablebelow were coated using a Waterproof® CV coater (DuPont) with a #6 Meyerrod. The film was dried at 45° C. for 5 minutes. The thickness of thepigmented layer was 1.0 μm. Compositions are shown in Table 11.

TABLE 11 Ex. 20 Ex. 21 Ex. 22 Ex. 23 % (g) % (g) % (g) % (g) Blue 70.00035.000 70.0000 35.0000 70.0000 35.0000 70.0000 35.0000 PigmentDispersion P5 20.115 4.5700 15.2050 3.4600 10.4750 2.3800 5.3800 1.2200P1 2.3850 0.5400 2.2950 0.5200 2.0250 0.5000 2.1150 0.4800 P8 5 0.97 101.95 15 2.92 20 3.9 SDA 2.0000 0.1500 2.0000 0.1500 2.0000 0.1500 2.00000.1500 Zonyl ® FSA 0.5000 0.0375 0.5000 0.0375 0.5000 0.0375 0.50000.0375 H2O 8.7300 8.8900 9.0100 9.2100 Plasticizer 1.00% 2.00% 3.00%4.00% % Low Tg 9.00% 9.00% 9.00% 9.00% Solids   15% 7.5   15% 7.5   15%7.5   15% 7.5 TOTAL 50.000 50.0000 50.0000 50.0000

A three color filter on which red (Ex. 21) was transferred third andgreen and blue were transferred 1^(st) and 2^(nd), respectively is shownin FIG. 7.

1. In a donor element suitable for incorporation into a laserableassemblage, wherein the donor element comprises a substrate, a metallicor carbon heating layer, one or more transfer layers and an optionalejection layer, the improvement comprising a transfer layer deposited onsaid heating layer, said transfer layer comprising an imageablecomponent and a binder composition comprising a first polymeric binderand a second polymeric binder, said first polymeric binder beingcharacterized by a glass transition temperature at least 20 centigradedegrees higher than the glass transition temperature characteristic ofsaid second polymeric binder; wherein said first polymeric binder isselected from the group consisting of polystyrene and copolymersthereof, acrylites, methacrylates and co-polymers thereof, and whereinfurther said second polymeric binder is selected from the groupconsisting of butyl methacrylates and co-polymers thereof.
 2. Alaserable assemblage comprising: a donor element, wherein the donorelement comprises a substrate, a metallic or carbon heating layer, oneor more transfer layers and an optional ejection layer the donor elementfurther comprising a transfer layer deposited on said heating layer,said transfer layer comprising an imageable component a bindercomposition comprising a first polymeric binder and a second polymericbinder, said first polymeric binder being characterized by a glasstransition temperature at least 20 centigrade degrees higher than theglass transition temperature characteristic of said second polymericbinder; and a receiver element in effective contact with the transferlayer of the donor element; wherein said first polymeric binder isselected from the group consisting of polystyrene and copolymersthereof, acrylates, methacrylates and co-polymers thereof, and whereinfurther said second polymeric binder is selected from the groupconsisting of butyl methacrylates and co-polymers thereof.
 3. An imagedlaserable assemblage comprising an imageable component and a bindercomposition comprising a first polymeric binder and a second polymericbinder, said first polymeric binder being characterized by a glasstransition temperature at least 20 centigrade degrees higher than theglass transition temperature characteristic of said second polymericbinder; wherein said first polymeric binder is selected from the groupconsisting of polystyrene and copolymers thereof, acrylates,methacrylates and co-polymers thereof, and wherein further said secondpolymeric binder is selected from the group consisting of butylmethacrylates and co-polymers thereof.
 4. An image disposed upon asubstrate, the image comprising an imageable component and a bindercomposition comprising a first polymeric binder and a second polymericbinder, said first polymeric binder being characterized by a glasstransition temperature at least 20 centigrade degree higher than theglass transition temperature characteristic of said second polymericbinder, wherein said first polymeric binder is selected from the groupconsisting of polystyrene and copolymers thereof, acrylate,methacrylates and co-polymers thereof, and wherein further said secondpolymeric binder is selected from the group consisting of butylmethacrylates and co-polymers thereof.
 5. A color filter arraycomprising an image disposed upon a substrate, the image comprising animageable component and a binder composition comprising a firstpolymeric binder and a second polymeric binder, said first polymericbinder being characterized by a glass transition temperature at least 20centigrade degrees higher than the glass transition temperaturecharacteristic of said second polymeric binder; wherein said firstpolymeric binder in selected from the group consisting of polystyreneand copolymers thereof, acrylates, methacrylates and co-polymers thereofand wherein further said second polymeric binder is selected from thegroup consisting of butyl methacrylates and co-polymers thereof.
 6. Thedonor element of claim 1 or the laserable assemblage of claim 2 or theimaged laserable assemblage of claim 3 or the image disposed upon asubstrate of claim 4 or the color filter array of claim 5 wherein saidfirst polymeric binder is characterized by a glass transitiontemperature at least 80 centigrade degrees higher than the glasstransition temperature characteristic of said second polymer.
 7. Thedonor element of claim 1 or the laserable assemblage of claim 2 or theimaged laserable assemblage of claim 3 or the image disposed upon asubstrate of claim 4 or the color filter array of claim 5 wherein saidfirst polymeric binder is characterized by a glass transitiontemperature in the range of 70° C.-140° C. and said second polymericbinder is characterized by a glass transition temperature in the rangeof −40° C.-60° C.
 8. The donor element of claim 7 wherein said firstpolymeric binder is characterized by a glass transition temperature inthe range of 100° C.-140° C. and said second polymeric binder ischaracterized by a glass transition temperature in the range of −40°C.-0° C.
 9. The donor element of claim 1 or the laserable assemblage ofclaim 2 or the imaged laserable assemblage of claim 3 or the imagedisposed upon a substrate of claim 4 or the color filter array of claim5 wherein said binder composition comprises at least onecrosslinkablefunctional group.
 10. The donor element of claim 1 or thelaserable assemblage of claim 2 or the imaged laserable assemblage ofclaim 3 or the image disposed upon a substrate of claim 4 or the colorfilter way of claim 5 wherein said first polymeric binder and saidsecond polymeric binder comprise one or more crosslinkablefunctionalgroups.
 11. The donor element of claim 1 or the laserable assemblage ofclaim 2 or the imaged laserable assemblage of claim 3 or the imagedisposed upon a substrate of claim 4 or the color filter array of claim5 wherein the weight ratio of said first polymeric binder to said secondpolymeric binder is in the range of 60:40 to 95:5.
 12. The donor elementof claim 1 wherein the weight ratio of said first polymeric binder tosaid second polymeric binder is in the range of 75:25 to 92:8.
 13. Thelaserable assemblage of claim 2 or claim 3 wherein the receiver elementcomprises a crosslinkablebinder.
 14. The donor element of claim 1 or thelaserable assemblage of claim 2 or further comprising a polymericsubstrate and the heating layer deposited on said substrate.
 15. Thedonor element of claim 1 or the laserable assemblage of claim 2 whereina donor support is present.